(idiomatic) Hunting or seeking; prowling about.

(idiomatic) Not incarcerated or in captivity; not under control. / (slang, archaic) Out on a spree, or in search of adventure.

Used other than figuratively or idiomatically: see on, run. / (idiomatic) Fleeing. / (idiomatic) At a disadvantage; forced to abandon a position.

(philately, overprint on British Empire stamps) On Her (or His) Majesty's Service.

correct; accurate; absolutely right / excellent

(idiomatic) Obsessively in mind.

In a state of heightened vigilance, especially prior to battle.

Prepared to defend or protect against criticism, attack or aggression. / (sports) defending; playing a defensive game

(slang, Britain, New Zealand, Australia) A secondary lover, a mistress.

(of livestock) Not yet butchered. / Alive; embodied in a living animal (including a human); in working order. / (of a human activity, such as eating) While standing, walking, or running; on foot.